A quick example of the bleeding obvious: people speak differently in the UK and the US. If you’re an American fan of British TV shows—the originals, not the American remakes—you’re probably very aware that once in a while, the characters will utter a word that you won’t hear on the streets of your hometown.
But you may be surprised to know that some of the words we consider distinctly British today were once fairly common in the United States. Read on:
1 Tetchy, adjective
Someone who is tetchy is someone with a bad temper:
2 Amongst, preposition
While amongst is less favored than among in British English, it’s rarely seen at all in American English.
3 Marvelous, adjective
Sure, you can use amazing instead, but marvelous sounds so much more . . . marvelous:
4 Fortnight, noun
Something that happens once every fortnight is something that happens every two weeks:
5 Cheers, exclamation
In British English, cheers isn’t something you’d say when it’s time to have a drink. It’s a casual way to say “thank you”:
6 Rubbish, noun, adjective
You know this one, it has the same meaning as garbage. Plus, rubbish can be used as an adjective when you want to say that something is really bad:
7 Blimey, exclamation
If you ever get tired of saying “wow,” you might make an effort to bring blimey back:
8 Hoover, noun
A hoover is a device that uses suction to clean surfaces—a vacuum cleaner:
9 Bespoke, adjective
Before things were custom-made, they were bespoke, especially if they were suits:
10 Chap, noun
Chap is an informal way of referring to a male person, sort of like “dude”:
What are your favorite British words?
from Grammarly Blog https://www.grammarly.com/blog/british-words-americans-do-not-use/